The Signal Sustain is an item found at Link's Logic. When supplied by power from a Wire, the Signal Sustain will immediately supply power to its output, but when the supplied power is removed, the Signal Sustain will wait a certain amount of time before turning the output power off. The duration is indicated by the position of the white arrow along the black bar. Pressing the button will make the arrow go up slightly, increasing the duration. When the arrow reaches the top, it resets to the bottom. This functionality can be used to make automatic wood cutters.